A. Field of the Disclosure
The present disclosure relates generally to powered vehicles.
B. Background
Hand-pushed equipment is used for a wide variety of purposes. Generally speaking such hand-pushed equipment involves a carrier or other device with one or more mobile bearings (such as wheels, skids, rollers, or skis) and a handle system that allows a walking person to grip the equipment using his or her hands. The front mobile bearing or bearings allow the equipment to move in an arc of directions, either by swiveling or some other means; specific examples of such other means include having a single front wheel (such as on a wheelbarrow), one or more caster wheels, or one or more roller balls. This amounts to a simple steering mechanism, which allows the pusher to turn the equipment by exerting uneven force on the right and left sides of the equipment with his hands.
Examples of such hand-pushed equipment include a shopping cart, a wheelchair, a wheelbarrow, a luggage cart, a stroller, a hand truck, a sled, and a lawn mower. A more exotic example would be a hover-mower, which, although lacking the mobile bearings that are commonly used in other types of pushed devices, turns easily when a user exerts uneven force on the handle, as it is supported by an air cushion.
A serious limitation of such pushed equipment is that the user must be strong enough to walk and push the equipment with his arms for a sustained period of time. Disabled and elderly people thus cannot use them. As the population ages and becomes increasingly obese, this problem will almost certainly become more pronounced.
Solutions have been proposed to this problem, but so far with limited success. The most common solution has been to convert the pushed equipment itself into a powered vehicle. Typically this involves adding an integral seat and engine to the equipment. It increases the cost, weight, space, and energy required to move the equipment. Such vehicles must be specially purchased, and generally cannot be simply added to existing pushed devices. One common example is the riding shopping cart. Riding shopping carts must be purchased in addition to a store's normal stock of shopping carts, and will of course remain idle until a person unable to use a manual shopping cart requires them. The storage basket of a riding shopping cart must be very small, because the sitting rider has a shorter reach than he would while standing. The sitting rider faces challenges in reaching items on higher shelves; the rider may be unable to rise to reach such items, or may endure undue stress in doing so.